I just saw a notification about the release on my Mac. I'm in no rush to upgrade just yet as there seems to be too much music software out there that is still not compatible. Having checked System Report to see which apps are still 32 bit I found these listed.

Amplitube 3 and Custom Shop (IK Multimedia)
AriaReporter (Plogue Art)
AudioChordWizard (PG Music)
AuthorisationManager (IK Multimedia)

I know IK Multimedia are working on upgrades, along with Native Instruments and many others.

Tim.